1. Field of the Invention
The present invention relates to communication system for performing telephone communication or facsimile transmission by utilizing computer terminals such as personal computers and the like.
2. Description of the Related Art
For such a purpose, there has conventionally been available an apparatus, wherein a personal computer is directly connected to a subscriber""s line by fitting a facsimile card or a modem card into the PCMCIA (Personal Computer Memory Card International Association) card slot of the computer.
This apparatus has only a single function system that a card must be prepared for every facsimile transmission or data communication and a PCMCIA card must be replaced by another in order to change a function. It also has a drawback that one computer may monopolize the subscriber""s line.
There is another apparatus designed for the same purpose, wherein a plurality of computers are connected to a local area network (Intranet) and further connected to a public switched telephone network by a gate way having a facsimile function or a data communication function. These apparatus allow a plurality of terminals to individually make calls and seemingly share the subscriber""s line, since these terminals are connected to the gate way. However, as a telephone number is not assigned to each computer, direct communication addressed to each computer from the public switched telephone network may not be performed and sharing of the subscriber""s line is not provided in the true sense of the word. As in the case of the PCMCIA card, this gate way must be prepared for every function and thus this may also has only a single function system.
In such conventional communication system, it is necessary to install large-sized and complicated equipment in order to utilize various functions of the computer by the subscriber""s line or an extension line. Therefore, it has been difficult to make sufficient use of various functions of the computer.
The invention was made to cope with the above-noted situation. Accordingly, it is an object of the present invention to provide a communication system, wherein a computer terminal may communicate with other communication terminals by a public switched telephone network or an extension network with a computer network connected to a subscriber""s line or an extension line.
It is another object of the invention to provide a communication system, whereby a plurality of computer terminals may share a subscriber""s line and one computer terminal may be utilized as a terminal for various kinds of communication services.
It is yet another object of the invention to provide a private branch exchange, whereby an exchanging operation may be performed for a computer terminal by connecting a computer network to communication highways included therein and the computer terminal may be treated equally with other extension terminals connected to the communication highways or other communication terminals connected to the communication highways by a public switched telephone network.
In order to achieve these objects, according to one aspect of the present invention, a communication system comprises exchanging means including a plurality of communication circuits having communication highways of a plurality of channels, exchange control means for controlling the exchanging means, a computer network connected to the exchange control means and having at least one computer terminal, and data converting means connected between the computer network and the communication highways. The computer terminal comprises control information communicating means for transmitting and receiving call control information with the exchange control means by the computer network and data communicating means for transmitting and receiving data with the data converting means by the computer network. The data converting means comprises mode converting means for converting the mode of transmitted data between the computer network and the communication highways.
According to another aspect of the present invention, a communication system comprises a computer terminal and converting means connected to the digital circuits of a computer network and a public switched telephone network. The computer terminal comprises control information communicating means for transmitting and receiving call control signal with the converting means by the computer network when the terminal communicates with another communication terminal connected to the public switched telephone network, and data communicating means for transmitting and receiving data with the converting means by the computer network. The converting means comprises call control signal transfer means for transferring call control signal between the digital circuits of the computer network and the public switched telephone network, and data converting means for converting the mode of transmitted data between the computer network and the digital circuits of the public switched telephone network.
In accordance with yet another aspect of the present invention, a computer system, connected to a computer network and capable of communicating plural kinds of data, comprises a plurality of communication highways in which a plurality of time slots are time-division multiplexed, an exchange including a time switch for switching the plurality of communication highways wherein each time slot of the communication highways is respectively assigned to any of the plural kinds of data, and interface means connected between the computer network and one of the plurality of communication highways, and for connecting one computer terminal in the computer network to the time slot in accordance with the data type in the communication highway.
In accordance with a further aspect of the present invention, a private branch exchange having a computer terminal capable of communicating plural kinds of data and the terminal is connected to a computer network, comprises a plurality of communication highways in which a plurality of time slots are time-division multiplexed wherein each time slot of the communication highways is respectively assigned to any of the plural kinds of data, a time switch for switching the plurality of communication highways, and interface means connected between the computer network and one of the plurality of communication highways, and for connecting one computer terminal in the computer network to the time slot in accordance with data type in the communication highway.
Additional objects and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.
The objects and advantages of the present invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.